114 THE LIMITATIONS OF SCIENCE 



on postulates which are determined by experience and 

 generally accepted as true; the causes of phenomena 

 and the discussion of the postulates of science lie in the 

 province of the metaphysician. This differentiation in 

 method of thought cannot be rigidly adhered to since 

 the boundary line is more or less obscure, and is liable 

 to considerable displacement as a science advances ; but 

 the acceptance of this principle would prevent much of 

 the confusion which has been introduced into science 

 by writers who have not recognized it to be a general 

 rule. For example, the principle of relativity is not 

 strictly a physical law but the expression, in mathe- 

 matical symbols, of the general philosophical law of the 

 finite nature of the human mind which has been ac- 

 cepted for centuries. Again, the discussion of the 

 shape of the atom or electron is not a physical prob- 

 lem, as it is incapable of verification by experience. 

 This does not mean that such questions should not be 

 discussed, but the method of their discussion and the 

 results obtained are properly the method and results 

 of metaphysics and are not in the category of physical 

 phenomena and laws. 



In the first place, men of science must accept the 

 existence of an objective universe, whose phenomena 

 and laws are external to our intelligence and will. 

 But, since the interpretation of phenomena is sub- 

 jective and thus conditioned by our intelligence and 

 will, scientific laws are governed by the mathematical 



